Winch and control means therefor

ABSTRACT

A winch for use on a mobile crane to hoist or lower a load comprises a hydraulic winch motor, a shaft driven thereby, a winch drum, and planetary gearing through which the shaft drives the drum. A three-position hydraulic control valve controls motor speed and direction of rotation. The winch further comprises a brake disc connected by a uni-directional clutch to the shaft and spring-applied, hydraulic brake cylinder-released brake pads for frictional engagement with the brake disc. A two-position hydraulic brake valve controls operation of the brake cylinder. Both the control valve and brake valve are part of a control means which further includes a control lever and linkage. The control lever acts through the linkage and is movable from a neutral position (wherein both valves are closed) toward a winchlower position (wherein the brake valve opens before the control valve) and toward a winch hoist position (wherein the brake valve remains closed but the control valve opens). During lowering, the winch drum starts rotating smoothly as the brake is released and the load begins to descend under the force of gravity before lowering power is applied to the winch motor. During a winchhoist operation, the uni-directional clutch allows winch drum rotation even though the brake is still applied.

United States Patent [1 1 Witwer [4 1 Dec.4,1973

[ WINCH AND CONTROL MEANS THEREFOR [75] Inventor: Wallace J. Witwer,Cedar Rapids,

Iowa

[73] Assignee: Harnisckfeger Corporation,

Milwaukee, Wis.

22 Filed: Feb. 24, 1972 21 Appl. No.: 229,056

[52] U.S. Cl. 254/150 FH, 254/150 R [51] Int. Cl B66d 1/30 [58] Field ofSearch 212/55, 58, 59;

192/3 R; 254/186, 150, 150 R, 150 PH, 180; l37/625.69, 636, 636.1;188/712 Primary Examiner-Richard E. Aegerter Assistant Examiner.1osephE. Valenza Attorney-James E. Nilles [5 7 ABSTRACT A winch for use on amobile crane to hoist or lower a load comprises a hydraulic winch motor,a shaft driven thereby, a winch drum, and planetary gearing throughwhich the shaft drives the drum. A threeposition hydraulic control valvecontrols motor speed and direction of rotation. The winch furthercomprises a brake disc connected by a uni-directional clutch to theshaft and spring-applied, hydraulic brake cylinderreleased brake padsfor frictional engagement with the brake disc. A two-position hydraulicbrake valve controls operation of the brake cylinder. Both the controlvalve and brake valve are part of a control means which further includesa control lever and linkage. The control lever acts through the linkageand is movable from a neutral position (wherein both valves are closed)toward a winch-lower position (wherein the brake valve opens before thecontrol valve) and toward a winch hoist position (wherein the brakevalve remains closed but the control valve opens). During lowering, thewinch drum starts rotating smoothly as the brake is released and theload begins to descend under the force of gravity before lowering poweris applied to the winch motor. During a winchhoist operation, theuni-directional clutch allows winch drum rotation even though the brakeis still applied.

8 Claims, 7 Drawing Figures WINCH AND CONTROL MEANS THEREFOR BACKGROUNDOF THE INVENTION Field of Use This invention relates generally tohydraulic winches, hoists or the like and, particularly, to controlmeans therefor whereby operation of the winch drive motor and winchbrake are coordinated.

Description of the Prior Art Mobile cranes and similar equipment employa winch rotatable in opposite directions to hoist or lower a load. Somewinches are driven by a hydraulic motor and employ a spring-set,hydraulically released brake. Both the motor and the brake are operatedby suitable control means. In practice, it is normally necessary torelease the brake prior to rotation of the winch motor and, in someequipment, control means are provided to effect automatic operation ofthe winch motor in a desired direction immediately upon release of thebrake so as to prevent a load from falling uncontrolled. In some priorart winches and control means therefor, the hydraulic brake cylinder wasdirectly connected to the hydraulic circuit for the winch motor and acounterbalance valve was provided which caused the winch motor tooperate in the lowering direction as soon as the brake was released.This arrangement has two drawbacks. First, it is possible for a fallingload to overtake and use up the available oil supply to the motor and,consequently, to interfere with proper operation of the brake. Second,the aforesaid arrangement does not permit of smooth operation in loadhandling because power lowering takes place immediately upon release ofthe brake. It is desirable, therefore, to provide improved winches andcontrol means therefor which overcome these drawbacks and have otheradvantages.

SUMMARY OF THE INVENTION In accordance with the present invention thereis provided a winch for a mobile crane or the like which is rotatable ineither hoist or lower direction by a hydraulic motor and employeshydraulically releasable brake means. The winch comprises a hydraulicwinch motor, a shaft driven thereby, a winch drum, and planetary gearsconnected between the shaft and the winch drum to drive the latter. Thebrake means comprise a brake disc connected through a uni-directionalclutch to the aforesaid shaft, brake pads for frictional engagement withthe brake disc, spring means normally acting to bias the pads againstthe disc, and a hydraulic brake cylinder pressurizable to release thebrake pads. Pressurization of the brake cylinder is controlled by meansof a two-way or two-position brake valve. The motor is controlled bymeans of a three-way control valve. The control valve and brake valveare both operated by means comprising a three-position control lever anda linkage between the control lever and the valves.

With the control lever in neutral, the brake valve is closed and thecontrol valve is in neutral. This results in the brake being set and themotor being stationary. When the control lever is moved from neutraltoward lower position, the brake valve opens first to' release thebrake, the winch begins to rotate under the force of the load, andsubsequently the control valve opens to effect lowering operation of themotor and power lowering of the load. This sequence allows for smoothwinch operation. When the control lever is moved from neutral towardhoist position, the brake valve remains closed and the brake remains setbut the control valve opens to effect hoisting operation of the motorand hoisting of the load. This sequence is possible because theunidirectional clutch between the brake disc and motor shaft allows forrelative rotation therebetween in the hoist direction with the brakeset.

The aforedescribed operations are effected by the control lever actingthrough a linkage constructed in accordance with the invention andconnected to the brake valve and the control valve. The valves arearranged in side-by-side relationship and each valve comprises alinearly movable valve spool, the stem of which extends therefrom. Thecontrol stem or spool has a neutral position and is movable outwardly towinch lower position and inwardly to winch hoist position. The brakevalve stem or spool has a neutral, closed or brake-applied position andis movable inwardly to brake-release position. The control lever isrigidly connected to a hub or member which is rotatably about a fixedpoint. The hub or member comprises outwardly extending arms. Lost-motionconnection means are connected between the arms and the valve spools.For example, one arm carries a pin which is slideably engageable in aslot in a first link which is pivotably connected to the spool of thecontrol valve. The other arm carries a pin which is pivotably connectedto a plate and the plate has a slot which is slideably engageable with apin on the spool of the brake valve. The plate is provided with a stoppin or projection which is biased into engagement with the said otherarm by means of a tension spring connected between the plate and themember. Pivoting of the control lever from neutral toward winch-lowerposition results in force being transmitted to move the brake valvespool inwardly from closed position to fully open position (to effectrelease of the brake) prior to force being transmitted to move thecontrol valve spool outwardly from neutral toward winch-lower position.When the brake valve spool bottoms out in fully open position, furthermovement of the control lever and further outward movement of thecontrol valve spool is possible to increase lowering speed of the winchbecause the plate pivots on its arm. Pivoting of the control lever fromwinch-lower position back to neutral results in return of the controlvalve spool to neutral and subsequent reclosure of the brake valve.Pivoting of the control lever from neutral toward hoist position resultsin force being transmitted to move the control valve spool inwardly fromneutral position toward hoist position but does not result in anymovement of the brake valve spool. Pivoting of the control lever fromhoist position back to neutral results in return of the control valvespool to neutral but does not result in any movement of the brake valvespool.

DRAWINGS FIG. 1 is a perspective view of a mobile crane incorporating awinch in accordance with the invention;

FIG. 2 is an enlarged cross-section view of the winch shown in FIG. 1;

FIG. 3 is a schematic view of a hydraulic control circuit for a winch inaccordance with the invention;

FIG. 4 is a view showing the brake valve and control valve of FIG. 3 inlowering position;

FIG. 5 is a view showing the brake valve and control valve of FIG. 3 inhoist position;

FIG. 6 is an enlarged side elevational view of the control valve andbrake valve shown in FIG. 3; and

FIG. 7 is a detail of the linkage taken on line 7-7 of FIG. 6.

DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 shows a mobile crane 10having a winch 12 in accordance with the present invention. Mobile crane10 comprises an upper crane portion 14 which is mounted for rotationabout a vertical axis on the platform 16 of a mobile carrier 18. Uppercrane portion 14 comprises a housing 20 to which the lower end of amovable boom 22 is attached for pivotal movement vertically. Winch 12 ismounted on the top rear of housing 20 and is provided with a line 24 forhandling a load 26. Line 24 is reeved over a pulley 28 at the end ofboom 22. Winch 12 is operable in either the hoist or lower direction andis braked by means of suitable controls (not shown in FIG. 1) which areunderstood to be located in an operators cab 30 in housing 20 of crane10.

Referring to FIG. 2, winch 12 is shown in cross section and comprises asupporting framework 32, on which a conventional hydraulic winch motor34 is rigidly mounted. Winch motor 34 comprises an output shaft 36,rotatable in either direction, which is connected to a drive shaft 38which is supported for rotation on supporting frame-work 32. Winch 12further comprises a winch drum 44 which is mounted for rotation onsupporting framework 32 by means of bearings 46 and 48. Drive shaft 38is connected through a planetary gear means or mechanism 50 to drum 44to effect rotation thereof as hereinafter explained. It is to beunderstood that when hydraulic motor 34 is energized for rotation ineither direction it effects corresponding rotation of drive shaft 38and, through the planetary gear mechanism 50, effects correspondingrotation of winch drum 44.

The planetary gear mechanism 50 connecting the drive or input shaft 38with the output member or drum 44 comprises the following. A sun gear 51is fixed on shaft 38 for rotation therewith and is also in constant meshwith a plurality of planetary gears 52 which are circumferentiallyspaced around a revolvable carrier 53. The planetary gears 52 are alsoin constant mesh with an internal ring gear 54 which is fixed in thehousing of support 32. The carrier 53 also includes an inner member 55which has internal gears 56 that mesh with a compound gear 57 whichrotates freely with respect to shaft 38. The compound gear 57 alsoincludes a gear portion 58 which is in constant mesh with another set ofplanetary gears. 59 that are circumferentially spaced around androtatably mounted in another carrier 60. The planetary gears 59 are alsoin constant mesh with a large internal ring gear 61 also rigidly fixedin the housing of support 32. The revolvable carrier has internalsplines 62 by means of which it is rotationally fixed to a sleeve 63.The sleeve 63 is mounted on suitable anti-friction bearings 48 and has akey or spline connection 65 with the interior of the drum 44.

Winch 12 further comprises braking means for preventing drum rotationunder certain conditions. As FIG. 2 shows, the braking means comprise abrake disc 72 which is mounted on a conventional uni-directional clutch74 which, in turn, is mounted on drive shaft 38. It is to be understoodthat when shaft 38 rotates in the hoist direction, there is relativemovement between brake disc 72 and drive shaft 38 because of the actionof uni-directional clutch 74. However, when drive shaft 38 rotates inthe lowering direction, brake disc 72 is rotatable therewith. The brakemeans further comprise two caliper brake assemblies, each of whichcomprises two brake pads 78, a hydraulic brake cylinder 80, and brakespring means 82. The brake pads 78 are movably mounted on a bracket 84which is supported on supporting framework 32 of winch 12. The brakepads 78 are movable by means of a rod 86 from an open or brake-releaseposition wherein they are disengaged from brake disc 72 to a closed orbrake-applied position wherein they engage brake disc 72. The brake pads78 are normally biased to brake-applied position against brake disc 72by the brake spring means 82 acting through rod 86. However, uponpressurization of brake cylinder 80 from a suitable source of hydraulicfluid, the brake pads 78 are moved against the bias of the brake springs82 by rod 86 to disengaged position clear of brake disc 72. When thebrake pads 78 engage brake disc 72 they prevent rotation of brake disc72, drive shaft 38 and drum 44 in the winch-lower direction. However,when the brake pads 78 engage brake disc 72 while hydraulic motor 34 andshaft 38 are energized for rotation in the winch-hoist direction, theydo not prevent rotation of the motor, drive shaft or drum in the hoistdirection because of the operation of unidirectional clutch 74.

FIG. 3 is a schematic diagram of the hydraulic control system for winchmotor 34 and brake cylinders 80 of the brake means. It is to be notedthat motor 34 and brake cylinder 80 are supplied with hydraulic fluidfrom separate pumps 110 and 102, respectively, so that fluid loss in onedoes not affect the other. Only one brake cylinder 80 is shown in FIG.3.

As FIG. 3 shows, brake cylinder 80 comprises a housing 88 having apiston 90 therein which is spring loaded by a return spring 92. Housing88 is provided with a fluid port 94 which is connected by a hydraulicfluid line 96 to a winch brake valve 98. Valve 98 is also connected by afluid line 100 to a conventional hydraulic brake valve pump 102 and byanother fluid line 104 to a hydraulic fluid reservoir 107.

Brake valve 98, shown schematically in FIG. 3, is a conventionaltwo-position type hydraulic valve having a movable valve spool 106 whichis shown in brakeapplied position in FIG. 3 and is movable leftward(with respect to FIG. 3) by means of a valve stem 108 to brake-releasedposition. With brake valve 98 in brake-applied position, fluid line 100is connected to fluid line 104 and fluid flow from pump 102 is divertedto reservoir 107. Furthermore, in brake-applied position, fluid line 96is connected to fluid line 104 and any fluid in housing 88 of brakecylinder 80 is exhausted to reservoir 107 as biasing spring 92 biasespiston 90 leftward (with respect to FIG. 3) to brake-applied position.This allows the brake pads 78 shown in FIG. 2 to engage brake disc 72.With brake valve 98 in brakereleased position, fluid line 100 isconnected to fluid line 96 and fluid flow from pump 102 pressurizesbrake cylinder 80 to move piston 90 rightward (with respect to FIG. 3)against the bias of spring 92 to brake-release position and causes thebrake pads 78 shown in FIG. 2 to disengage from brake disc 72.

Hydraulic motor 34 of winch 12 is supplied with hydraulic operatingfluid for rotation in either direction at a desired speed from aconventional hydraulic winch motor pump 110 and fluid flow between pump110 and motor 34 is controlled by a conventional three-way orthree-position winch control valve 112. Hydraulic winch motor 34 is aconventional hydraulic motor having two fluid ports 114 and 116 anddirection of rotation of motor 34 is determined by which of the twoports is pressurized. Speed of rotation of motor 34 is determined by theamount of pressurization. It may be assumed for purposes of discussionthat when port 114 of motor 34 is energized, winch 12 rotates in thewinchlower direction and when port 116 is energized, the winch rotatesin the winch-hoist direction.

Control valve 112, shown schematically in FIG. 3, is a conventionalthree-position type hydraulic valve (similar to that shown in U.S. Pat.No. 3,295,551) having a movable valve spool 118 which is shown inneutral position in FIG. 3 and is movable rightward (with respect toFIG. 3) from neutral to winch-lower position and leftward from neutralto winch-hoist position. Movement of valve spool 118 is effected by avalve stem 120. As hereinafter explained, valve stem 108 of brake valve98 and valve stem 120 of control valve 112 are both operated incoordination by a valve control means comprising a single control lever122 and a linkage 124. The extent of movement in either direction fromneutral of spool 118 of control valve 112 regulates the amount ofpressurization of hydraulic motor 34 and thereby controls motor speed.

Control valve 112 is connected by a fluid supply line 126 to pump 110and by a fluid return line 128 to reservoir 107 through fluid line 104.Control valve 112 is also connected by fluid lines 130 and 132 to theports 114 and 116, respectively, of winch motor 34. A conventional lowpressure relief valve 138 is connected in fluid line 128. A conventionalanti-void poppet valve 134 and a main relief unloader valve 136 areconnected between fluid supply line 126 and fluid return line 128. Aconventional spring-loaded check valve 140 is connected between fluidline 132 and fluid return line 128. A similar check valve 142 isconnected between fluid line 130 and fluid return line 128. When spool118 of control valve 112 is in neutral position, as shown in FIG. 3,fluid flow from pump 110 to motor 34 is blocked and is diverted throughcontrol valve 112, to reservoir 107.

When control valve spool 118 is moved to winchlower position (i.e.,rightward with respect to FIGS. 3 and 4), fluid supply line 126 frompump 110 is connected through control valve 112 to fluid line 130 toeffect pressurization of port 114 of winch motor 34. Port 116 of motor34 is then connected through fluid line 132, valve 112, fluid line 128and low pressure relief valve 138 to reservoir 107. In this condition,control valve effects rotation of winch motor in the winchlowerdirection As hereinbefore noted, the extent of such rightward movementof valve spool 118 determines the speed of rotation of winch motor 34and winch drum 44.

When control valve spool 118 is moved leftward with respect to FIGS. 3and 5 from neutral position, the fluid lines 126 and 128 are connectedto the fluid lines 132 and 130 by control valve 112, respectively,thereby effecting pressurization of port 116 of winch motor 34. Thiscauses rotation of winch motor 34 and winch drum 44 in the winch-hoistdirection and the extent of leftward movement of valve spool 118controls the speed of rotation.

FIG. 6 is an enlarged side elevational view of control valve 112 andbrake valve 98 shown in FIG. 3 and shows their physical configurationand mechanical interconnection. As FIG. 6 shows, brake valve 98 andcontrol valve 112 are rigidly mounted on a suitable supporting structure146 which is understood to be located in the operators cab 30 of crane10. Control valve 112 is physically located above brake valve 98 andboth valves are disposed so that their spools 118 and 106, respectively,which extend from the ends of the valve housings are in parallelrelationship. The spools 118 and 106 operate or are moved linearly inresponse to the movement of control lever 122 which acts through linkage124. Linkage 124 comprises a pivotally movable member 148, in the formof a hub 150, which is mounted for limited rotation on bearing means 152on a fixed shaft 154 about a point. Shaft 154 is rigidly supported on ahousing 156 on supporting structure 146. Control lever 122 is rigidlyattached to hub of member 148 and effects rotational movement thereof.In FIG. 6 control lever 122 is shown in neutral position and isunderstood to be movable counterclockwise or downwardly (with respect toFIG. 6) to winch-lower position and also movable clockwise or upwardlyto winch-hoist position. Movable member 148 is provided with upper andlower arms 158 and 160, respectively, which are rigidly secured to hub150 and extend therefrom. Upper and lower arms 158 and 160 are providedwith rigidly attached pins 162 and 164, respectively, at their extremeends. An upper or first link 166 is connected between pin 162 on upperarm 158 and a pin 170 on valve stem 120 of control valve 112. Link 166is held in place on the pins 162 and 170 by means of a washer 172 andcotter pins 176 and 178, respectively. Link 166 is provided with a slot180 which slidably engages pin 162 on arm 158 and serves as alost-motion connection which allows for limited play or travel betweenpin 162 and link 166 as control lever 122 is moved from neutral towardwinch-lower position.

The pin 164 on lower arm 160 pivotally engages a hole 182 in a secondlink or toggle plate 184 which is connected to valve stem 108 of brakevalve 98. Plate 184 is provided with a slot 186 which slidably engages apin 188 on the end of shaft 190 which is pivotably connected to valvestem 108 by a pin 192. Pin 188 is secured in slot 186 by means of awasher 194 and cotter pin 196. Plate 184 is connected by biasing meansin the form of a tension spring 198 to a projection 200 on hub 150.Spring 198 engages a hole 202 in projection 200 and a pin 204 on plate184. Plate 184 is provided with stop means such as a stop projection orstop pin 206 which abuts or engages a side of lower arm 160.

FIG. 6 shows control lever 122 in neutral position, control valve 112 inneutral position, and brake valve 98 in brake-applied position. Rotationof control lever 122 downwardly from neutral toward winch-lower positionresults in force being transmitted by arm 160 to plate 184 to move brakevalve stem 108 inwardly (rightward in FIG. 6) from brake-appliedposition to brake-release position to effect release of the brake. Thismovement occurs prior to force being transmitted by arm 158 to link 166to move control valve stem 120 outwardly from neutral toward hoist-lowerposition. When the brake valve spool 106 bottoms out in full rightwardposition, further movement of control lever 122 and further outwardmovement (leftward in FIG. 6) of the control valve spool 118 is possibleto increase lowering speed of motor 34 because the plate 184 is able topivot with respect to arm 160 and shaft 190. R0-

tation of control lever 122 from hoist-lower position back to neutralresults in return of control valve spool 118 to neutral prior to returnof brake valve spool 106 to brake-applied position. Rotation of controllever 122 from neutral toward winch-hoist position results in forcebeing transmitted by arm 158 to link 166 to move control valve spool 118inwardly from neutral position toward winch-hoist position but suchmovement does not result in any movement of brake valve spool 106because plate 184 is able to move with respect to pin 188. Rotation ofcontrol lever 122 from winch-hoist position back to neutral resutls inreturn of control valve spool 118 to neutral but, again, does not resultin any movement of brake valve spool 106.

OPERATION Winch 12 of crane 10 operates as follows. Assume that bothpumps 102 and 110 are in operation, that control lever 122 is inneutral, that brake valve 98 is in brake-applied position, and thatcontrol valve 112 is in neutral position. With these assumptions, winchmotor 34, winch shaft 36 and winch drum 44 are stationary, winch brakecylinder 80 is depressurized and the brake pads 78 engage brake disc 72.

To operate winch 12 in the winch-lower direction, control lever 122 ismoved counterclockwise (with respect to FIG. 6) from neutral towardwinch-lower position. As this occurs, valve spool 106 of brake valve 98is moved inwardly from brake-applied to brake-release position, brakecylinder 80 becomes pressurized, and the brake pads 78 disengage frombrake disc 72. Winch drum 44 is now free to rotate in the winch-lowerdirection and begins to do so as load 26 on line 24 of crane 10 beginsto descend under the force of gravity. At this point, a smoothtransition has occurred as load begins to descend under the force ofgravity. As control lever 122 is moved further toward winch-lowerposition, valve spool 118 of brake valve 98 bottoms out in fully openposition, and linkage 124 causes valve spool 118 of control valve tocommence movement outwardly with respect to FIG. 6) from neutral towardwinchlower position. Such movement causes port 114 of winch motor 34 tobecome pressurized and the motor begins rotation in the winch-lowerdirection. Motor 34 drives shaft 38, and the latter, acting through theplanetary gears 50, causes winch drum 44 to be driven in the winch-lowerdirection. Winch drum 44 is already rotating but now driven for rotationat a faster speed. At this point another smooth transition in drumrotation has occurred. Further, movement of control lever 122 in thewinch-lower direction causes an increase in the speed of winch motor 44.Reverse movement of control lever 122 (short of a full return toneutral) results in a decrease in the speed of drum rotation.

When control lever 122 is returned to neutral, linkage 124 causes valvespool 118 of control valve 112 to return to neutral and effectdepressurization of port 114 of motor 34. Subsequent to this, linkage124 effects return movement of valve spool 106 of brake valve 98 tobrake-applied position, depressurization of brake cylinder 80, andre-engagement of the brake pads 78 with brake disc 72 to brake winch 12.

To operate winch 12 in the winch-hoist direction, control lever 122 ismoved clockwise (with respect to FIG. 6) from neutral toward winch-hoistposition. As this occurs, valve spool 118 of control valve 112 is movedinwardly by linkage 124 from neutral to winchhoist position. Suchmovement causes port 116 of winch motor 34 to become pressurized and themotor begins rotation in the winch-hoist direction. It is to be notedthat such movement of control lever 122 does not result in any movementof brake valve spool 106 because the spool is not movable outwardlybeyond its brake-applied position. However, slot 186 in plate 184 oflinkage 124 permits plate 184 to move clockwise sufficiently withrespect to pin 186 to allow for inward movement of valve spool 118 ofcontrol valve 112. Since, brake valve 98 is still in brake-appliedcondition, brake cylinder remains depressurized and the brake pads 78still engage brake disc 72. However, unidirectional clutch 74 betweenbrake disc 72 and motor shaft 36 and drive shaft 38, allows both theseshafts to rotate in the winch-hoist direction despite the fact that thebrake is still applied. Further movement of control lever 122 in thewinch-hoist direction causes an increase in the speed of winch motor 44.Reverse movement of control lever 122 (short of a full return toneutral) results in a decrease in the speed of drum rotation.

When control lever 122 is returned to neutral, linkage 124 causes valvespool 118 of control valve 112 to return to neutral and effectdepressurization of port 116 of motor 34. However, valve spool 106 ofbrake valve 98 does not move from brake-applied position. Since thebrake is still applied, rotation of winch drum 44 in the winch-lowerdirection is prevented.

RESUME A winch 12 for use on a mobile crane 10 to hoist or lower a load26 comprises a hydraulic winch motor 34, a shaft 38 driven thereby, awinch drum 44, and planetary gearing 50 through which the shaft 38drives drum 44. A three-position hydraulic control valve 112 controlsmotor speed and direction of rotation. The winch 12 further comprises abrake disc 72 connected by a uni-directional clutch 74 to the shaft 38and springsapplied brake pads 78 for frictional engagement with thebrake disc 72. The brake pads 78 are released from engagement with disc72 by pressurization of a hydraulic brake cylinder 80. A two-positionhydraulic brake valve 98 controls operation of the brake cylinder 80.Both the control valve 112 and brake valve 98 are operated by the samecontrol lever 122 through a linkage 124 which is movable from a neutralposition (wherein both valves 112 and 98 are closed) toward a winchlowerposition (wherein the brake valve 98 opens before the control valve 112)and toward a winch hoist position (wherein the brake valve 98 remainsclosed by the control valve 112 opens). During lowering, the winch drum44 starts rotating smoothly as the brake is released and the load 26causes the winch to start rotating by gravity before lowering power isapplied to the winch motor 34. During a winch-hoist operation, theuni-directional clutch 74 allows winch drum 44 rotation even though thebrake pads 78 still engage the brake disc 72.

The invention allows for a smooth transition in winch drum speed duringa lowering operation. The linkage provides compact, simplified, positivecontrol for the two valves being operated. The fluid supply for thebrake valve and brake cylinder are separate from the fluid supply forthe control valve and winch motor so that loss of pressure in one doesnot affect operation of the other.

I claim:

1. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom, awinch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprising,a shaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrakeapplied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, controlvalve means for said motor, brake valve means for said brake means, andcontrol means for operating said control valve means and said brakevalve means, said control means including a movable control leverconnected to and for operating both said valve means, said control leverbeing operable in the winch-lower direction to effect operation of saidbrake valve means and release of said brake means and to effectsubsequent operation of said control valve means and operation of saidmotor in the winch-lower direction.

2. A combination according to claim 1 wherein said control means foroperating said valve means are operable in the winch-hoist direction toeffect operation of said control valve means and effect operation ofsaid motor in the winch-hoist direction while permitting said brakevalve means and brake means to remain in the brake-applied positions.

3. A combination according to claim 2 wherein said control means foroperating said valve means comprises a movable control lever and alinkage connected between said control lever and said control valvemeans and said brake valve means.

4. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom, awinch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprising,a shaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrakeapplied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, controlvalve means for operating said motor in the winch-hoist and winch-lowerdirection, brake valve means for applying and releasing said brakemeans, and control means for operating both of said valve means, saidcontrol means for operating both of said valve means comprising acontrol lever connected to both of said valve means and movable towinch-hoist and winch-lower directions, said control lever beingoperable in the winch-lower direction to effect operation of said brakevalve means and release of said brake means prior to operation of saidcontrol valve means and operation of said motor in the winch-lowerdirection, said control lever being operable in the winchhoist directionto effect operation of said control valve means and operation of saidmotor in the winch-hoist direction while said brake valve means andbrake means remain in the brake-applied position.

5. A combination according to claim 4 wherein each of said valve meanscomprises a movable valve stem for effecting operation thereof andwherein said control means for operating said valves further comprises alinkage connected between said control lever and each valve stem.

6. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom, awinch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprising,a shaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrakeapplied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, a controlvalve for said hydraulic motor having a neutral position, a winch-hoistposition and winch-lower position, a brake valve for said brake cylinderhaving a brake-applied position and a brake release position, a controllever for said control valve and for said brake valve, said controllever having a neutral position, a winch-hoist position and a winchlowerposition, and a linkage comprising lost-motion connection meansconnected between said control lever and said control valve and saidbrake valve, said linkage, when said control lever is moved from neutralto lower position, effecting movement of said brake valve tobrake-release position and subsequently effecting movement of saidcontrol valve to winch-lower position, and said linkage, when saidcontrol lever is moved from neutral to winch-hoist position, effectingmovement of said control valve to winch-hoist position but permittingsaid brake valve to remain in brakeapplied position.

7'. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom, awinch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprising,a shaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrakeapplied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, said brakemeans comprising a brake and hydraulic brake cylinder connected to saidbrake and operable to effect release of said brake, a control valve forsaid hydraulic motor and comprising a movable valve stem having aneutral position, a winch-hoist position and a winch-lower position, abrake-valve for said brake cylinder and comprising a movable valve stemhaving a brake-applied position and a brake-release position, said brakevalve stem when in brake-release position effecting operation of saidbrake cylinder, a control lever connected to said control valve stem andto said brake stem, said control lever having a neutral position, awinch-hoist position and a winch-lower position, and a linkagecomprising lost-motion connection means connected between said controllever and said control valve stem and said brake valve stem, saidlinkage, when said control lever is in neutral position, maintainingsaid control valve stem in neutral position and said brake valve stem inbrake-applied position, said linkage, when said control lever is movedfrom neutral to lower position, effecting movement of said brake valvestem to brake-release position and subsequently effecting movement ofsaid control valve stem to winch-lower position, and said linkage, whensaid control lever is moved from neutral to winch-hoist position,effecting movement of said control valve stem to winch-hoist positionbut permitting said brake valve stem to remain in brake-appliedposition.

8. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom,

a winch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprisinga hydraulic motor, a shaft driven by said motor, a winch drum and gearmeans connected between said shaft and said drum to effect rotation ofsaid drum; brake means for said winch comprising a brake disc, aunidirectional clutch for connecting said disc to said shaft, a caliperbrake assembly comprising brake pads for engagement with said disc,spring means for normally biasing said pads against said disc, and ahydraulic brake cylinder pressurizable to release said pads from saiddisc, a threeposition control valve for said motor and comprising aspool having a neutral position, a hoist position and a lower position,a source of pressurized hydraulic fluid for said control valve, atwo-position brake valve for said brake cylinder and comprising a spoolhaving a brake-closed position and a brake release position, a source ofpressurized hydraulic fluid for said brake valve, control means for saidvalves comprising a control lever and a member pivotably movablethereby, said member having first and second arms and being movableabout a point in response to movement of said control lever, first andsecond pins on said first and second arms, respectively, a first linkpivotably connected between said first pin and the spool of said controlvalve, said first link being provided with a slot in which said firstpin is engaged, a second link pivotably connected between said secondpin and the spool of said brake valve, said second link being providedwith a slot in which a pin on said brake valve spool is engaged, a stopprojection on said second link cngageablc with said second arm, and abiasing spring connected between said second link and said hub.

1. A crane having a main frame, a boom pivotally mounted on said framefor vertical swinging relative thereto, said boom comprising a pluralityof telescoping boom sections for changing the length of the boom, awinch on said frame, a load line connected to said winch and trainedover a free end of said boom for engaging a load, said winch comprising,a shaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrake-applied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, controlvalve means for said motor, brake valve means for said brake means, andcontrol means for operating said control valve means and said brakevalve means, said control means including a movable control leverconnected to and for operating both said valve means, said control leverbeing operable in the winch-lower direction to effect operation of saidbrake valve means and release of said brake means and to effectsubsequent operation of said control valve means and operation of saidmotor in the winch-lower direction.
 2. A combination according to claim1 wherein said control means for operating said valve means are operablein the winch-hoist direction to effect operation of said control valvemeans and effect operation of said motor in the winch-hoist directionwhile permitting said brake valve means and brake means to remain in thebrake-applied positions.
 3. A combination according to claim 2 whereinsaid control means for operating said valve means comprises a movablecontrol lever and a linkage connected between said control lever andsaid control valve means and said brake valve means.
 4. A crane having amain frame, a boom pivotally mounted on said frame for vertical swingingrelative thereto, said boom comprising a plurality of telescoping boomsections for changing the length of the boom, a winch on said frame, aload line connected to said winch and trained over a free end of saidboom for engagIng a load, said winch comprising, a shaft, a hydraulicmotor for driving said winch through said shaft in winch hoist and winchlower directions, a unidirectional clutch on said shaft, and hydraulicbrake means for said winch connected to said unidirectional clutchmeans, said hydraulic brake means having brake-applied and brake-releasepositions, said unidirectional clutch means enabling said winch to beoperated in the hoist direction when said hydraulic brake means are inbrake applied position and enabling braking of said winch when thelatter is operated in the lower direction and said hydraulic brake meansare in brake applied position, control valve means for operating saidmotor in the winch-hoist and winch-lower direction, brake valve meansfor applying and releasing said brake means, and control means foroperating both of said valve means, said control means for operatingboth of said valve means comprising a control lever connected to both ofsaid valve means and movable to winch-hoist and winch-lower directions,said control lever being operable in the winch-lower direction to effectoperation of said brake valve means and release of said brake meansprior to operation of said control valve means and operation of saidmotor in the winch-lower direction, said control lever being operable inthe winch-hoist direction to effect operation of said control valvemeans and operation of said motor in the winch-hoist direction whilesaid brake valve means and brake means remain in the brake-appliedposition.
 5. A combination according to claim 4 wherein each of saidvalve means comprises a movable valve stem for effecting operationthereof and wherein said control means for operating said valves furthercomprises a linkage connected between said control lever and each valvestem.
 6. A crane having a main frame, a boom pivotally mounted on saidframe for vertical swinging relative thereto, said boom comprising aplurality of telescoping boom sections for changing the length of theboom, a winch on said frame, a load line connected to said winch andtrained over a free end of said boom for engaging a load, said winchcomprising, a shaft, a hydraulic motor for driving said winch throughsaid shaft in winch hoist and winch lower directions, a unidirectionalclutch on said shaft, and hydraulic brake means for said winch connectedto said unidirectional clutch means, said hydraulic brake means havingbrake-applied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, a controlvalve for said hydraulic motor having a neutral position, a winch-hoistposition and winch-lower position, a brake valve for said brake cylinderhaving a brake-applied position and a brake-release position, a controllever for said control valve and for said brake valve, said controllever having a neutral position, a winch-hoist position and awinch-lower position, and a linkage comprising lost-motion connectionmeans connected between said control lever and said control valve andsaid brake valve, said linkage, when said control lever is moved fromneutral to lower position, effecting movement of said brake valve tobrake-release position and subsequently effecting movement of saidcontrol valve to winch-lower position, and said linkage, when saidcontrol lever is moved from neutral to winch-hoist position, effectingmovement of said control valve to winch-hoist position but permittingsaid brake valve to remain in brake-applied position.
 7. A crane havinga main frame, a boom pivotally mounted on said frame for verticalswinging relative thereto, said boom comprising a plurality oftelescoping boom sections for changing the length of the boom, a winchon said frame, a load line connected to said winch and trained over aFree end of said boom for engaging a load, said winch comprising, ashaft, a hydraulic motor for driving said winch through said shaft inwinch hoist and winch lower directions, a unidirectional clutch on saidshaft, and hydraulic brake means for said winch connected to saidunidirectional clutch means, said hydraulic brake means havingbrake-applied and brake-release positions, said unidirectional clutchmeans enabling said winch to be operated in the hoist direction whensaid hydraulic brake means are in brake applied position and enablingbraking of said winch when the latter is operated in the lower directionand said hydraulic brake means are in brake applied position, said brakemeans comprising a brake and hydraulic brake cylinder connected to saidbrake and operable to effect release of said brake, a control valve forsaid hydraulic motor and comprising a movable valve stem having aneutral position, a winch-hoist position and a winch-lower position, abrake-valve for said brake cylinder and comprising a movable valve stemhaving a brake-applied position and a brake-release position, said brakevalve stem when in brake-release position effecting operation of saidbrake cylinder, a control lever connected to said control valve stem andto said brake stem, said control lever having a neutral position, awinch-hoist position and a winch-lower position, and a linkagecomprising lost-motion connection means connected between said controllever and said control valve stem and said brake valve stem, saidlinkage, when said control lever is in neutral position, maintainingsaid control valve stem in neutral position and said brake valve stem inbrake-applied position, said linkage, when said control lever is movedfrom neutral to lower position, effecting movement of said brake valvestem to brake-release position and subsequently effecting movement ofsaid control valve stem to winch-lower position, and said linkage, whensaid control lever is moved from neutral to winch-hoist position,effecting movement of said control valve stem to winch-hoist positionbut permitting said brake valve stem to remain in brake-appliedposition.
 8. A crane having a main frame, a boom pivotally mounted onsaid frame for vertical swinging relative thereto, said boom comprisinga plurality of telescoping boom sections for changing the length of theboom, a winch on said frame, a load line connected to said winch andtrained over a free end of said boom for engaging a load, said winchcomprising a hydraulic motor, a shaft driven by said motor, a winch drumand gear means connected between said shaft and said drum to effectrotation of said drum; brake means for said winch comprising a brakedisc, a unidirectional clutch for connecting said disc to said shaft, acaliper brake assembly comprising brake pads for engagement with saiddisc, spring means for normally biasing said pads against said disc, anda hydraulic brake cylinder pressurizable to release said pads from saiddisc, a three-position control valve for said motor and comprising aspool having a neutral position, a hoist position and a lower position,a source of pressurized hydraulic fluid for said control valve, atwo-position brake valve for said brake cylinder and comprising a spoolhaving a brake-closed position and a brake release position, a source ofpressurized hydraulic fluid for said brake valve, control means for saidvalves comprising a control lever and a member pivotably movablethereby, said member having first and second arms and being movableabout a point in response to movement of said control lever, first andsecond pins on said first and second arms, respectively, a first linkpivotably connected between said first pin and the spool of said controlvalve, said first link being provided with a slot in which said firstpin is engaged, a second link pivotably connected between said secondpin and the spool of said brake valve, said second link being providedwith a slot in which a pin on said brake valve spool is engaged, a stopprojection on said second link engageable with said second arm, and abiasing spring connected between said second link and said hub.